Plasma pre-treatment and TiO_2 coating of PMMA for the improvement of antibacterial properties

摘要

The antibacterial properties of polymethyl methacrylate (PMMA) are enhanced by coating with TiO_2 films. The transparent TiO_2 films on plasma-treated PMMA are prepared by sol-gel dip coating. The modified surfaces are characterized by XRD, AFM, ATR-FTIR, SEM, UV-vis spectroscopy, and contact angle measurements. Finally, the antibacterial properties are evaluated using the method of plate-counting of Staphylococcus aureus (gram positive) and Escherichia coli (gram negative). It is found that the anatase-TiO_2 film is well-conglutinated on PMMA surface with an average crystallite size of ca. 4nm. The as-prepared TiO_2/PMMA exhibits excellent photoinduced antibacterial effect for the sterilization of bacteria under indoor natural light, and about 100% of both bacteria are inactivated within 2h illumation. Compared to PMMA without any treatment, the superior anti-adhesion capability of the TiO_2/PMMA surface is also demonstrated.